Alarm clocks are ubiquitous and inexpensive. Efforts have been made to improve the basic alarm, because many individuals find the audible alarm annoying. For example, U.S. Pat. No. 7,280,439 describes a “countermeasure for circadian and sleep disruption as caused by a traditional alarm clock.” It incorporates a lighting system at the alarm clock that, prior to the preset waking time, will emit a light that gradually increases in intensity as it changes the ultraviolet spectrum of light it emits, so as to simulate the rising sun.
Improved alarm clocks are desired.